1. Field of the Invention
This invention generally relates to a drug combination including an anti-proliferative drug such as everolimus and an anti-inflammatory agent such as clobetasol for the treatment of a disorder such as restenosis and vulnerable plaque.
2. Description of the Background
Plaques have been associated with stenosis and restenosis. While treatments of plaque-induced stenosis and restenosis have advanced significantly over the last few decades, the morbidity and mortality associated with vascular plaques have remained significant. Recent work suggests that plaque may generally fall into one of two different general types: standard stenotic plaques and vulnerable plaques. Stenotic plaque, which is sometimes referred to as thrombosis-resistant plaque, can generally be treated effectively by the known intravascular lumen opening techniques. Although plaques induce stenoses, these atherosclerotic plaques themselves are often a benign and are an effectively treatable disease.
Unfortunately, as plaque matures, narrowing of a blood vessel by a proliferation of smooth muscle cells, matrix synthesis, and lipid accumulation may result in formation of a plaque which is quite different than a standard stenotic plaque. Such atherosclerotic plaque becomes thrombosis-prone, and can be highly dangerous. This thrombosis-prone or vulnerable plaque may be a frequent cause of acute coronary syndrome.
While the known procedures for treating plaque have gained wide acceptance and shown good efficacy for treatment of standard stenotic plaques, they may be ineffective (and possibly dangerous) when thrombotic conditions are superimposed on atherosclerotic plaques. Specifically, mechanical stresses caused by primary treatments like percutaneous transluminal intervention (PTI), such as stenting, may actually trigger release of fluids and/or solids from a vulnerable plaque into the blood stream, thereby potentially causing a coronary thrombotic occlusion. For example, rupture of the fibrous cap that overlies the thrombogenic necrotic core is presently believed to play an important role in acute ischemic events, such as stroke, transient ischemic attack, myocardial infarction, and unstable angina (Virmani R, et al. Arterioscler Thromb Vasc Biol. 20: 1262-1275 (2000)). There is evidence that fibrous cap can be ruptured during stent deployment. Human data from various sources have indicated that lipid rich and/or positively remodeled and/or echolucent lesions in sysmptomatic coronary atherosclerosis have higher likelihood for restenosis (See, for example, J. Am. Coll. Cardiol. 21(2):298-307 (1993); Am. J. Cardiol. 89(5):505 (2002); Circ. 94(12):3098-102 (1996)). Therefore, there is a need for the treatment of vulnerable plaques and restenosis.
The embodiments of the present invention address these and other needs.